Electrically-conductive probe tips are utilized, for example, in power scanning microscopy, scanning channel microscopy, etc., as scanning needles with Van der Waals' alternating fields or in magnetic fields, or with tunnel probes for the measurement of the tunnel current. They may, of course, be used elsewhere, wherever fine measurements or inputs with electrical probes are required.
The characteristics of such probe tips will generally depend upon the application, but the probes must be fabricated, especially in scanning microscopy, with sufficient precision to provide the measurements necessary for the qualitative and quantitative evaluation of the scanning points. It is thus important to provide a method of producing such probe tips that the characteristics of the tips will be highly reproducible. It has been proposed heretofore to make such tips by electrolytic machining of the tip from an electrically conductive wire.
It is known, for instance, to connect a wire of electrically conductive material as an electrode and to immerse it in an electrolyte. The material of the wire is electrically eroded until the wire forms the probe tip.
These earlier systems are not as precise and reproducible as is desirable.
In this connection reference may be had to two German patent documents, DE-OS 25 32 719 and DE-OS 33 29 482.